1. Field of Invention
This invention relates to tape measures, more specifically to a straight edge or T-square attachment device designed for use with a standard tape measure to assist in the framing of conventional stud walls and a variety of construction applications.
2. Description of Related Art
Tape measures and T-squares are commonly used by carpenters to make accurate measurements on pieces of lumber. The importance of accurate measurements is instantly recognizable, and therefore of great concern when building a stable structure. Typically, carpenters must first measure the object to be marked and thereafter use a different tool, a T-square or a protractor, to sketch a line at a desired angle. This is of course, an efficient method of marking an object. Thus, the need for a combined tape measure and T-square tool has given rise to the present invention - an attachable T-square for use with a conventional tape measure having a scale for determining a variety of angles.
Accordingly, combined tools like the one described above have been previously attempted. For example, U.S. Pat. No. 5,671,543 to Sears proposes a pivotally attached marking or cutting device for a tape measure. Hastings, U.S. Pat. No. 5,481,810, proposes a removably attachable right triangle. However, while both of the previous devices do provide means for marking an object, neither offers a method for measuring angles.
A T-square accessory is proposed by Meyers, U.S. Pat. No. 5,113,596, wherein a T-square is offered as a complement to a standard tape measure. However, there are several disadvantages to Meyers, which the present invention overcomes. As an example, Meyers does not provide a compact T-square accessory because of the shape and position of the straight edge portion; attaching a device to a belt or a carpenter's apron would be very awkward. The present invention has the straight edge in a more convenient location and thus overcomes this fault. Additionally, Meyers does not offer any means for measuring and marking a variety of angles.
U.S. Pat. No. 4,965,944 to Kuze et al. appears to disclose a tape measure casing having an angle scale for measuring and marking a range of angles. This device does not incorporate a T-square and, by virtue of its design, eliminates access to the carrying clip, thereby denying the user a method of transporting it except by carrying it in a hand or by placing it in a pocket.
Lastly, U.S. Pat. No. 4,106,201 to Hansen proposes a case for a standard tape measure having a pivotally attached retractable square blade structure. This device is capable of marking a line perpendicular to the longitudinal axis of the marking tape, but has no means for determining other angles.
Thus, the foregoing devices fail to teach or suggest a variable angle T-square and tape measure apparatus which has the following combination of desirable features: (1) provides a compatible combination of both a tape measure and a T-square; (2) permits convenient attachment and detachment of the T-square apparatus from the tape measure; (3) permits the use of a conventional tape measure; (4) permits the tape measure to be used without interference from the T-square; and (5) allows various predetermined angles to be measured and marked.